title: Impaired saccadic adaptation in DYT11 dystonia.
abstract: BACKGROUND
  Recent neuroimaging studies point to a possible pathophysiological role of cerebellar dysfunction in dystonia. The authors investigated the association between sensorimotor adaptation, cerebellar dysfunction and the myoclonus-dystonia phenotype.
  
  
  METHODS
  The authors prospectively analysed reactive saccade adaptation in a genetically homogeneous group of 14 patients with DYT11 dystonia owing to a mutation of the SGCE gene. The authors used a backward reactive saccade adaptation task, a well-characterised experimental oculomotor paradigm involving the cerebellum. The principle of this paradigm is to simulate a spatial error in saccade generation by systematically shifting a visual target during saccade execution. Repetition of this systematic error induces a gradual decrease in the initial saccade amplitude, reflecting an adaptive phenomenon.
  
  
  RESULTS
  Saccade adaptation was significantly lower in the DYT11 patients than in healthy controls (mean value: 8.9%±4.5% vs 21.6%±4.5%; p=8.3×10(-6)). The time course of adaptation also differed between the patients and controls (p=0.002), reflecting the slower saccadic adaptation in the patients.
  
  
  CONCLUSIONS
  This study provides the first neurophysiological evidence of cerebellar dysfunction in DYT11 dystonia and supports a role of cerebellar dysfunction in the myoclonus-dystonia phenotype.
authors.affiliation: Assistance Publique Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Neurology, Paris, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Hubsch
authors.forename: Marie
authors.initials: M
authors.lastname: Vidailhet
authors.forename: Sophie
authors.initials: S
authors.lastname: Rivaud-Péchoux
authors.forename: Pierre
authors.initials: P
authors.lastname: Pouget
authors.forename: Vanessa
authors.initials: V
authors.lastname: Brochard
authors.forename: Bertrand
authors.initials: B
authors.lastname: Degos
authors.forename: Denis
authors.initials: D
authors.lastname: Pélisson
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Golmard
authors.forename: Bertrand
authors.initials: B
authors.lastname: Gaymard
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Roze
mesh_terms: D000293:Adolescent; D002526:Cerebellar Diseases / Q000235:genetics* / Q000503:physiopathology*; D002531:Cerebellum / Q000503:physiopathology; D020821:Dystonic Disorders / Q000235:genetics* / Q000503:physiopathology*; D056228:Feedback, Sensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D010641:Phenotype; D012438:Saccades / Q000235:genetics* / Q000502:physiology*; D049031:Sarcoglycans / Q000235:genetics*
chemical_list: D049031:Sarcoglycans